Identification of naïve HVC-4 patients who may be treated with pegylated-interferon and ribavirin according to IL28B polymorphisms

Role of IL28B genotype in the liver stiffness increase in untreated patients with chronic hepatitis C

The role of interleukin (IL)28B has been deepened in the treatment response to pegylated-interferon in patients affected by chronic hepatitis C (CHC). However, recently the IL28B genotypes were also related to hepatic fibrosis progression in untreated patients, using the liver biopsy. The aim of this prospective and longitudinal study was to assess the role of different IL28B genotypes in the liver stiffness progression in a cohort of untreated subjects affected by CHC. We included in this analysis all untreated patients affected by CHC and followed for at least 5years with the annual evaluation of liver stiffness using Fibroscan®. All enrolled subjects were genotyped for rs8099917 and rs12979860 IL28B polymorphisms. In the study period, 266 patients were considered. After 5years we observed the following median stiffness increases: 6.7kPa [5.1-7.8] in TT/CC, 4.9kPa [4.1-5.0] in TT/TC, 3.4kPa [3.2-3.8] in TG/TC and 1.7kPa [1.2-1.9] in GG/TT. These values were statistically significant in all groups (p<0.001). In the multivariate analysis resulted as predictive factors of liver stiffness progression the following: IL28B TT/CC genotype (OR=4.571; 95%IC=2.381-12.994; p<0.001) and IL28B GG/TT genotype (OR=0.510; 95%IC=0.289-0.712; p=0.007). In this study we evidenced that IL28B genotypes were associated with a different level of liver stiffness increase after 5years and could be used to select the patients who should be treated with priority.

Treatment with PEG-IFN and ribavirin in patients with chronic hepatitis C, low grade of hepatic fibrosis, genotype 1 and 4 and favorable IFNL3 genotype: A pharmacogenetic prospective study

The new direct-acting antivirals agents (DAAs) rapidly changed the treatment approach in chronic hepatitis C (CHC); however, the interferon (IFN)-free therapies availability is currently different in some countries, due to higher costs of these drugs. Naïve treated patients, who are not eligible for IFN-free therapies, could be selected for standard dual treatment with pegylated (PEG)-IFN and ribavirin (RBV), through IFN lambda 3 gene polymorphisms and fibrosis stage evaluation. Inclusion criteria were: naïve treated CHC patients with GT1 or GT4, without major contraindication to PEG-IFN or RBV, with fibrosis stage F0-F2 and IFNL3 rs8099917/rs12979860 TT/CC genotypes. 65 patients were included in the study. Overall SVR was observed in 50 patients (76.9%); SVR rates among different genotypes were as follows: 15 with GT1a (71.4%), 27 with GT1b (79.4%) and 8 for GT4 (80%). The RBV cutoff at 2weeks of 1800ng/mL, predictor of RVR, was determined (p=0.003; sensibility=60.4%, specificity=88.2%, positive predictive value=88.9%, negative predictive value=100%). In multivariate analysis, factors significantly associated with treatment failure were living alone condition (OR=4.302; 95%IC=1.254-16.257; p=0.034) and RBV plasma level <1800ng/mL at 2weeks (OR=4.970; 95%IC=1.405-17.565; p=0.009). Considering a pharmacogenetic-guided approach, dual therapy with PEG-IFN and RBV can be considered a reliable option for patients ineligible for IFN-free treatments, who are motivated and well informed about all the aspects related to PEG-IFN administration.

Pharmacogenetics of ribavirin-induced anemia in HCV patients

Dual therapy (pegylated interferon plus ribavirin) was considered the standard of care for hepatitis C virus (HCV) treatment until 2011, when the first-wave direct-acting antivirals were added to this regimen for HCV genotype-1 patients to increase the sustained virological response rate. The second-wave direct-acting antivirals entered the clinical use also in some ribavirin (RBV)- and/or interferon-free combinations. Nevertheless, since some of the new therapeutic regimens also include RBV and its use results still associated with hemolytic anemia, this requires countermeasures to be prevented. These include the identification of several host predictive factors involved in RBV absorption, distribution, metabolism, elimination and many others that might influence this toxic effect. For this reason, we provided an overview of the potential role of pharmacogenomics in predisposing RBV-treated HCV patients to anemia.

Role of genetic polymorphisms in hepatitis C virus chronic infection

AIM: To analyze the host genetics factors influencing the clinical course and the response to antiviral treatment in patients with chronic hepatitis C (CHC).

METHODS: We conducted an electronic search on the PubMed and MEDLINE (2000-2014) databases and Cochrane library (2000-2014). A total of 73 articles were retrieved and their data were extensively evaluated and discussed by the authors and then analyzed in this review article.

RESULTS: Several studies associated polymorphisms in the interleukin 28B gene on chromosome 19 (19q13.13) with a spontaneous viral clearance in acute hepatitis C and with the response to pegylated interferon (Peg-IFN)-based treatment in chronic hepatitis C patients. Other investigations demonstrated that inosine triphosphate pyrophosphatase genetic variants protect hepatitis C virus-genotype-1 CHC patients from ribavirin-induced anemia, and other studies that a polymorphism in the patatin-like phospholipase domain-containing protein 3 was associated with hepatic steatosis in CHC patients. Although not conclusive, some investigations suggested that the vitamin D-associated polymorphisms play an important role in the achievement of sustained virologic response in CHC patients treated with Peg-IFN-based antiviral therapy. Several other polymorphisms have been investigated to ascertain their possible impact on the natural history and on the response to treatment in patients with CHC, but the data are preliminary and warrant confirmation.

CONCLUSION: Several genetic polymorphisms seem to influence the clinical course and the response to antiviral treatment in patients with CHC, suggesting individualized follow up and treatment strategies.

Differential distribution of IL28B.rs12979860 single-nucleotide polymorphism among Egyptian healthcare workers with and without a hepatitis C virus-specific cellular immune response

The CC genotype of the interleukin (IL)-28B.rs12979860 gene has been associated with spontaneous hepatitis C virus (HCV) clearance and treatment response. The distribution and correlation of an IL28B.rs12979860 single-nucleotide polymorphism (SNP) with HCV-specific cell-mediated immune (CMI) responses among Egyptian healthcare workers (HCWs) is not known. We determined this relationship in 402 HCWs who serve a patient cohort with ~85% HCV prevalence. We enrolled 402 HCWs in four groups: group 1 (n = 258), seronegative aviremic subjects; group 2 (n = 25), seronegative viremic subjects; group 3 (n = 41), subjects with spontaneously resolved HCV infection; and group 4 (n = 78), chronic HCV patients. All subjects were tested for an HCV-specific CMI response using an ex-vivo interferon-gamma (IFNγ) ELISpot assay with nine HCV genotype-4a overlapping 15-mer peptide pools corresponding to all of the HCV proteins. All subjects were tested for IL28B.rs12979860 SNP by real-time PCR. An HCV-specific CMI was demonstrated in ~27% of the seronegative aviremic HCWs (group 1), suggesting clearance of infection after low-level exposure to HCV. The frequency of IL28B.rs12979860 C allele homozygosity in the four groups was 49%, 48%, 49%, and 23%, while that of the T allele was 14%, 16%, 12 and 19%, respectively, suggesting differential distributions among subjects with different HCV status. As reported, IL28B.rs12979860 predicted the outcome of HCV infection (p < 0.05), but we did not find any relationship between the IL28B genotypes and the outcome of HCV-specific CMI responses in the four groups (p > 0.05). The data show differential IL28B.rs12979860 genotype distribution among Egyptian HCWs with different HCV status and could not predict the outcome of HCV-specific CMI responses.

Intracellular accumulation of boceprevir according to plasma concentrations and pharmacogenetics

Boceprevir (BOC) is a directly-acting antiviral agent for the treatment of hepatitis C virus genotype 1 (HCV-1) infection. It is a mixture of two stereoisomers, the inactive R and the active S isomers. No data have previously been published on BOC intracellular accumulation. In this study, BOC isomer concentrations in peripheral blood mononuclear cells (PBMCs) and plasma were determined. The influence of various single nucleotide polymorphisms (SNPs) on plasma and intracellular drug exposure at Week 4 of triple therapy were also evaluated. Plasma and intracellular BOC concentrations were determined at the end of the dosing interval (C(trough)) using a UPLC-MS/MS validated method. Allelic discrimination was performed through real-time PCR. Median plasma concentrations were 65.97 ng/mL for the S isomer and 36.31 ng/mL for the R isomer; the median S/R plasma concentration ratio was 1.66. The median PBMC concentration was 2285.88 ng/mL for the S isomer; the R isomer was undetectable within PBMCs. The median S isomer PBMC/plasma concentration ratio was 28.59. A significant positive correlation was found between plasma and PBMC S isomer concentrations. ABCB1 1236, SLC28A2 124 and IL28B rs12979860 SNPs were associated with the S isomer PBMC/plasma concentration ratio. In regression models, S isomer plasma levels and FokI polymorphism were able to predict S isomer intracellular exposure, whereas SNPs in AKR1, BCRP1 and SLC28A2 predicted the S isomer PBMC/plasma concentration ratio. No similar data regarding BOC pharmacogenetics and pharmacokinetics have been published previously. This study adds a novel and useful overview of the pharmacological properties of this drug.

Treatment optimization of naïve HCV-1 patients using IL28B, RVR and fibrosis stage

The treatment of patients with HCV genotype 1 is quickly changing. The clinician could optimize the selection of patients who may benefit from standard therapy with pegylated-interferon and ribavirin instead of more expensive new combinations with the directly acting antivirals. We retrospectively examined in our cohort of 232 patients with genotype 1 infection the role of interleukin 28B (both rs8099917 and rs12979860), fibrosis stage and rapid virological response. Global SVR in TT/CC patients was 88.3% (98% in F0-F1, 80% in F2-F3); in TT/TC was 68.2 (85% in F0-F1, 71.4% in F2-F3). Rapid virological response was related to rs12979860 CC genotype but is not useful to predict the virological response in TG/GG patients at rs8099917. The standard dual therapy may be successfully administered in all TT/CC and TT/TC patients without F4 fibrosis score. Conversely, patients with TG/CC or GG/CC genotypes should be treated with other therapeutic options.

Current status and emerging challenges in the treatment of hepatitis C virus genotypes 4 to 6

Hepatitis C virus (HCV) genotypes 4, 5 and 6 are mainly present in Africa, the Middle East and Asia and they have been less extensively studied with respect to epidemiology, natural disease history and therapeutic endpoints. Response rates to a 48-wk combined peginterferon/ribavirin treatment range to 40%-69% for HCV 4, 55%-60% for HCV 5 and 60%-90% for HCV 6. Response-guided schedules are recommended to optimize the outcomes of peginterferon/ribavirin treatment in HCV 4 and, in form of preliminary data, for HCV 6, but no data are yet available to support such an individualization of therapy for HCV 5. Recently, the direct-acting antivirals (DAAs) with pan-genotypic activities simeprevir, sofosbuvir and daclatasvir have been recommended in triple regimens with peginterferon/ribavirin for the treatment of HCV genotypes 4 to 6 infections. In the future, DAA-based interferon-free therapies are awaited to drastically improve treatment outcomes in HCV. However, efforts to improve treatment outcomes with peginterferon/ribavirin should continue, as the HCV 4-6 infected population is mainly based in resource-limited settings with restricted access to the costly DAAs.